The invention relates to a new use for terguride and its physiologically compatible salts.
Terguride [3-(6-methylergolin-8.alpha.-yl)-1,1-diethyl-urea] is a known useful drug, e.g., for its nidation- and lactation-inhibiting as well as antipsychotic effects, e.g., upon oral administration to animal and man. These are believed due to its partial-agonistic action on dopamine receptors. (See, e.g, German Pat. No. 2,238,540 and DOS No. 3,129,714, which are entirely incorporated by reference.)
Furthermore, various other ergot alkaloids, for example, bromocryptine or lisuride, have been used in human medicin for hypertension therapy (Stumpe, K. O., Kolloch, R., Higuchi, M. K., Kruck, F., Vetter, H.: Hyperprolactinemia nad Antihypertensive Effect of Bromocryptine in Essential Hypertension, Lancet 2:211, 1977).
It is furthermore known that the neurotransmitter, dopamine, important not only for motor functions but also for psychic, cognitive and endocrine functions, suffers a decrease in effectiveness with increasing age. This occurs not only in test animals but as well in man and is believed due to lowered concentrations in the brain with increasing age (A. Carlsson and Winblad, B., J. Neural Transmission 38:271-276, 1976; Severson, J. A. and Finch, C. E., Brain Research 192:147-162, 1980). Parkinson's disease has been known for a long time as an extreme form of dopamine deficiency in the motor system. In its therapy, dopamine agonists such as L-dopa and bromocryptine have proven themselves well. However, these compounds have the drawback that they have such a strong effect on all dopamine receptors as to evoke, as side effects, also nausea, vomiting, orthostatic regulatory disturbances, and stupor.
It is likewise known to utilize other ergot alkaloids having a weakly dopaminergic activity--detectable only during long-term treatment, for example as a lowering of prolactin level--such as dihydroergotoxine for therapy in cognitive and vigilance disturbances as well as other disorders of the brain function in the aged (R. J. McDonald, Pharmacopsychiatry 12:407-422, 1979). This weakly effective dopamine agonist, however, has the disadvantage that its pronounced .alpha.-adrenolytic activity precludes the use of the relatively high doses required for the quick attainment of a stronger therapeutic effect.
It is impossible to provide acutely higher dosages of dihydroergotoxine since in such cases strong orthostatic reactions occur in addition to a lowering of the blood pressure conveyed dopaminergically.